Note also that zhwiki (and others?) profitably uses the first part of the path to do variant selection.
https://zh.wikipedia.org/wiki/User:Cscott uses the wiki default variant (if logged in, uses the variant from the user's preferences) https://zh.wikipedia.org/zh-hans/User:Cscott https://zh.wikipedia.org/zh-hk/User:Cscott etc use the specified variant.
I have a dream to eventually enable https://en.wikipedia.org/en-gb/Football in a similar fashion. --scott